FAQs

Why is agar preferred over gelatin or carrageenan in plant tissue culture and micropropagation?

Agar is the preferred solidifying matrix for plant micropropagation due to its absolute biological inertness, superior mechanical stability, and independent gelling mechanism. Unlike gelatin, which melts at standard plant incubation temperatures (25°C), agar remains perfectly solid up to 85°C. Unlike carrageenan or gellan gum, whose gelation properties shift dramatically depending on the specific concentration of divalent cations (Ca2+, Mg2+) or monovalent salts in the solution, agar forms its stable physical gel network purely through hydrogen bonding. This allows agronomists to alter plant hormone and nutrient levels freely without risking gel collapse or altering the micro-diffusion rates of vital nutrients to the plant rootlets.